1. Field of the Invention
The invention relates to paper making machines and in particular to an apparatus for winding a traveling paper web produced on a paper making machine.
2. Description of Related Technology
Carrier drum apparatus, also known as carrier drum reels, are known from the following publications:
(1) DE-GM 74 13 286; PA1 (2) DE-OS 19 35 584; PA1 (3) U.S. Pat. No. 2,915,255; PA1 (4) U.S. Pat. No. 4,179,330; PA1 (5) DE 41 23 761; PA1 (6) Company Brochure "Voith Carrier Drum Reel", No. 1736; 1 67 3000; (6/20/73); PA1 (7) DE-PS 40 07 329 C2; PA1 (8) GB 1 297 812; and PA1 (9) U.S. Pat. No. 1,923,670.
Carrier drum reels disclosed in the publications noted herein form the final group of a paper machine. They are utilized to wind up a finished paper web into a roll. In such an apparatus, a cylinder is used as the roll core. The cylinder is disposed parallel to a carrier drum and is supported with its bearing journals in forks of swivelable levers so that the cylinder can be swiveled about a portion of a periphery of the carrier drum. The cylinder may be positioned adjacent to the carrier drum in an upper apex region thereof. When a first portion of a paper web is wound on the cylinder, the cylinder is swung horizontally around about one quadrant of the carrier drum, preferably in a direction of removal of the paper from the paper machine.
Publication (1) discloses a drivable carrier drum cooperating with a cylinder disposed parallel to the carrier drum. The cylinder is swivelable about a periphery of the drum. A guide roll is disposed upstream of the carrier drum with reference to a direction of movement of a paper web through the paper machine. Publication (1) also discloses a pressure roll cooperating with the drum and pressing thereagainst.
From publication (2) it is known that by the combination of a carrier drum and a pressure roll, a slip-free transport of a paper web is possible.
Historically, the major consideration with regard to carrier drum reels of the type mentioned herein has been the quality of winding. It is believed that the fact that other paper properties might also be influenced significantly by the carrier drum reel has not been considered.
An important consideration in the making of paper, particularly graphic papers, is low dust contamination. Dust is highly undesirable, especially for the subsequent paper finishing processes and during printing. Although there are devices for removing dust from paper, it is desirable to produce the paper during the manufacturing process in such a way that as little dust as possible is produced. A classical method of dust reduction is to add adhesive to the paper pulp suspension before the paper machine or to spray the paper with an adhesive-like substances in the paper machine. However, this requires additional expenditure and does not always bring about the desired success.
The carrier drum reel can be a considerable source of dust under certain circumstances. In particular, slippage can occur between the surface of the carrier drum and the paper web looped around it and thus the side of the paper web facing the drum surface will be subjected to friction. Since at this point of the paper making process the paper web has a high dry content, typically about 97%, abrasion of the paper web may occur. This is especially inconvenient in the case of coated paper because the coating of the paper facing the drum surface can be abraded, which can lead to a paper Web having two differently textured sides. Also, in the case of highly filled papers, i.e., papers with a high filler content, abrasion can be especially disadvantageous.
Although it has previously been known that web slippage is disadvantageous (see publication (2)), so far it has not been known that the production of dust can be promoted by slippage of a paper web on a carrier drum.
A winding machine disclosed in DE 41 34 648 shows a paper web pressed against a supporting roll 8 with the aid of a free-running roll. In such an arrangement, the tension of the paper web before the winding stations is supposed to be interrupted.